Our general goal is to obtain detailed information on a molecular level about how proteins and lipids interact. A variety of biochemical and biophysical techniques will be applied to several select systems. We are primarily interested in studying purified proteins with measurable biological activity, and asking questions concerning both the structural and functional aspects of protein-lipid interactions. The emphasis of our study is the effect of lipids on the protein. The major project involves E. coli pyruvate oxidase. This is a lipid-requiring, peripheral membrane flavo-enzyme. Our work has resulted in a detailed view both of the consequences of lipid binding to this enzyme, and also the mechanisms involved. We are now primarily interested in obtaining information about those portions of the enzyme involved in membrane binding. We are also interested in purifying the integral membrane components of the E. coli respiratory chain and eventually reconstituting the system with pyruvate oxidase. The bacterial respiratory chain offers unique opportunities to learn about the structure and function of a complex, membrane-bound protein network. Energy transduction in E. coli, which couples respiration to ATP synthesis is accompanied by dramatic changes in the conformation of the bacterial envelope. We are studying these changes since this phenomenon may indicate an important coupling between membrane lipids and proteins. It is likely that the E. coli outer membrane is an active participant in this phenomenon. Bacitracin is a peptide antibiotic whose structure is known and which forms a complex with polyisoprenyl pyrophosphates. The complex formed with farnesyl pyrophosphate will serve as an excellent model for protein-lipid studies, centering around magnetic resonance techniques.